Microwaves produced by a radiofrequency probe have been highly successful in many surgical arenas including: ablation of the trigeminal ganglion in patients with trigeminal neuralgia, removal of irritable foci of the cardiac conducting system, ablation of the cystic duct, thoracic sympathectomy, and rhizotomy for control of cancer pain. The use of radiofrequency ablation techniques is preferable because it generally does not require hospitalization, it has minor complications if any, and it is associated with a rapid convalescence.
Recent work in the field has demonstrated the efficacy of this technique in the ablation of osteoid osteomas through percutaneous placement of the radiofrequency probes (Rosenthal et al., JBJS, 80-A(6): 815-821, 1998). The same authors have described the creation of a controlled area of marrow and cortical necrosis from 0.9 cm to 1.3 cm in diameter with this technique in the femur of dogs (Tillotson et al., Invest Radio, 24:888-892, 1989).
Epiphysiodesis or destruction of the growth plate is a common treatment for leg length discrepancy or angular deformities. The operation is effective by slowing the growth rate of the longer limb through selective destruction of one or more growth plates. Traditionally, epiphysiodesis has been achieved by mechanical obliteration of the growth plate cartilage (physis). The purpose of the surgery is to ablate the central portion of the physis, and with subsequent healing, to produce a bony bridge that tethers the physis and prevents further growth.
Current techniques used for epiphysiodesis involve opening cortical windows on both the lateral and medial sides of the bone adjacent to the growth plate. The growth plate is manually destroyed with curettes and drills. Generally, at least 50% of the growth plate must be removed symmetrically on both sides to maximize growth arrest. As the growth plates are not perfectly flat, there are significant technical challenges to ensure that the tip of the tool is in the plate and that it stays in place throughout the procedure. Complications such as breaching the anterior or posterior cortex of the femur have potentially serious consequences with risk of vascular injury or extrusion of bone particles into the joint. Further damage to the metaphyseal region of the bone may be incurred through excessive curettage and drilling.
Therefore, there is a need for a reliable and precise procedure which overcomes the complications in the prior art. The present invention addresses this need with the use of radiofrequency ablation.